Statistical properties of the well deformed Sm 153 , 155 nuclei and the scissors resonance

The nuclear level densities (NLDs) and the $\ensuremath{\gamma}$-ray strength functions ($\ensuremath{\gamma}\mathrm{SFs}$) of $^{153,155}\mathrm{Sm}$ have been extracted from ($d,p\ensuremath{\gamma}$) coincidences using the Oslo method. The experimental NLD of $^{153}\mathrm{Sm}$ is higher than the NLD of $^{155}\mathrm{Sm}$, in accordance with microscopic calculations. The $\ensuremath{\gamma}\mathrm{SFs}$ of $^{153,155}\mathrm{Sm}$ are in fair agreement with QRPA calculations based on the D1M Gogny interaction. An enhancement is observed in the $\ensuremath{\gamma}\mathrm{SF}$ for both $^{153,155}\mathrm{Sm}$ nuclei around 3 MeV in excitation energy and is attributed to the $M1$ scissors resonance (SR). Their integrated strengths were found to be in the range 1.3--2.1 and 4.4--6.4 ${\ensuremath{\mu}}_{N}^{2}$ for $^{153}\mathrm{Sm}$ and $^{155}\mathrm{Sm}$, respectively. The strength of the SR for $^{155}\mathrm{Sm}$ is comparable to those for deformed even-even Sm isotopes from nuclear resonance fluorescence measurements, while that of $^{153}\mathrm{Sm}$ is lower than expected.